In an in-vehicle display apparatus for producing a map display, it is known to make provisions to be able to connect an external storage medium containing an application program for providing an expanded display capability, and to connect via a single communication adapter an external CPU having a processing function for implementing the expanded capability in accordance with the application program (for example, refer to Patent Document 1).
On the other hand, in an in-vehicle apparatus such as a navigation apparatus or audio apparatus mounted in a vehicle for use, it is known to provide a slot for inserting a card such as a memory card or a PC card (for example, refer to Patent Document 2). Such cards include a card that is equipped with a tuner for receiving television broadcasts or a card that incorporates a communication module for adding a communication function to the in-vehicle apparatus. By inserting the card into the slot provided in the in-vehicle apparatus, a desired function can be selectively added to the in-vehicle apparatus.
A prior art example of an in-vehicle apparatus provided with such a card insertion slot is shown in FIG. 40. The prior art navigation apparatus shown in FIG. 40 has a display unit that doubles as a door panel; FIG. 40(a) is a perspective view showing a condition in which the display unit 1015A as the door panel is closed, and FIG. 40(b) is a perspective view showing a condition in which the display unit 1015A as the door panel is opened. A desired function can be added by inserting a PC card 1002 into the card insertion slot 1003 that becomes accessible when the display unit 1015A is opened, as shown in FIG. 40(b).    Patent Document 1: Japanese Unexamined Patent Publication No. H03-200446 (FIG. 1)    Patent Document 2: Japanese Unexamined Patent Publication No. 2007-193699 (FIG. 2)